South Dakota Native Plant Research
Fabaceae : Astragalus gilviflorus

Fabaceae : Astragalus gilviflorus


Download Seed: The blackish seeds of plains orophaca are 1.5-2 mm long. (47 KB)

Download Seedling: Seedling of plains orophaca grown in research greenhouses at SDSU. (92 KB)

Download Leaves (897 KB)

Download Mature plants (29 KB)

Family Name


Common Name

Plains milkvetch, plains orophaca

Native American Name

Lakota: núŋǧoka yazáŋ pȟežúta


Astragalus gilviflorus is a perennial, cushion-forming, acaulescent or very short-stemmed (<3 cm long) herb, covered with silvery ax-shaped hairs. The compound, alternate, petiolate, leaves, have conspicuous, membranous or chartaceous stipules that are persistent, clasping and forming a tube or sheath around the stem. The leaves are trifoliolate, sometimes odd pinnate with 5 leaflets, the leaflets oblanceolate, 5–20 mm long with entire margins. The inflorescences are axillary, globose capitate or subcapitate racemes with 1-6 flowers. The 5-lobed cylindrical calyx tube is hairy, 6-15 mm long with teeth 1.5-4 mm in length. The corolla is papilionaceous, the white petals are clawed (narrowed at the base), the banner is slightly reflexed, 15–30 mm long, the wings 12-24 mm long and the keel is 10–22 mm long, often purple-tipped. The fruit is a legume, 6-10 mm long, oblong or ellipsoidal, exserted from calyx, beaked, hairy, and contains 3-10 mitt shaped seeds. Prairie milkvetch blooms in May and June on rocky prairie hilltops, slopes or barren flats in western South Dakota.

Additional Notes

Plains orophaca is a curious addition to a rock garden. If forms mounds when grown under moister conditions and provides unique textures to a garden.

Horticulture Notes

Seed Collection: Collect seeds when pods have turned brown and begin to split.

Germination: Seeds require cold treatment and scarification to help with water entry into the seed. Fall planting will usually provide good germination in the spring.

Light: Full sun.

Soil: Very adaptable to many soil types as long as they are well drained.

Water: Prefers dryer conditions.

Fabaceae : Astragalus gilviflorus